Which of the factors below is NOT critical in developing good physical fitness? * environment
behavior
age
heredity

Age

Explanation:

Physical fitness has to do with the effective and efficient working of the body system which allows individuals to be healthy.

The factors that are critical in developing good physical fitness include the environment, the behavior of the individual and heredity. To maintain physical fitness, one should exercise, eat healthy, avoid smoking etc. Age is not a factor in physical fitness.

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.